What If You Moved an Entire City?

Coastal cities across the globe are planning how they will keep the sea away as it rises. One solution? Just move the city.

How much would it cost? How do you lift a building? Where is this already happening?

Populations of people are already fleeing climate change across the globe. In North America, the Alaskan village of Newtok was faced with a mega slump caused by melting permafrost.

As the layers of frozen soil melted, the ground became unstable. Homes started to sink and crumble. It took over 20 years of preparation for the 380 inhabitants of Newtok to move. And they only transplanted the people, not the buildings. But what would happen if a larger city had to move?

New York City is home to more than 8 million people, and more than 1 million buildings. It also faces an increasing risk of coastal flooding. Relocating that many people would be daunting enough. But throw in the challenges of moving all the buildings, and now you’ve got quite the puzzle for a team of engineers.

To prepare, you’d have to figure out where you’re going to place the new New York City. You’d have to clear the land of any obstacles, and maybe level it out if the area is especially hilly. You might even need to build new roads to get there.

Before you even begin moving buildings, you’d want to pour the foundations and install utilities. Aging pipes are an issue in older cities, so at least you’d have the opportunity to use new materials for sewage, water, and gas. Now you’d start transplanting structures. Because of how complicated and lengthy this is, you’d divide the city up into small sections and take a phased approach.

After making sure that all citizens of a specific section have moved to a temporary spot, you would disconnect all utilities and remove any wires above ground. Then you excavate the building by digging around it and cutting into the foundation walls. You’d insert steel beams into the foundation openings to bear the weight of the building.

Then, after placing hydraulic jacks underneath the steel beams, you’d lift the house. Because the hydraulic jack system keeps the house completely level, you can actually leave furniture inside.

With the building lifted above its foundation, you’d slide beams underneath it, which will help you pull the building onto special dollies with rubber tires. These dollies would be attached to a truck, and the truck would transport the structure to its new location.

Because the foundation is already poured, the building simply has to be lowered onto it. Connect the utilities, and you’re done. It’s kind of like magic, except with a lot of people, power, time, and money. How much time and money?

Well, the largest building ever moved was the Fu Gang Building, which weighs 15,140 tons (33.3 million lb). It was only moved 36 meters (118 ft), but took 11 days. The farther the structure has to travel, and the taller the building, the longer it will take.

You’d definitely need multiple crews of people working at the same time to move the city as quickly as possible. Kiruna, Sweden, is currently transplanting its city of almost 23 thousand people. They have been moving the town, piece by piece, since 2004.

Their new location is 4 km (2.5 miles) to the east. The move has already cost over $532 million, and the cost will likely double before the move is finished. Based on those numbers, moving the city of New York would cost more than 370 trillion dollars.

That’s a lot of money. But it could be cheaper than rebuilding the entire city. Moving a house costs between 50% to 75% of what a comparable new building would cost. It would also be more environmentally friendly, since you’d reuse old material. And in some cases, buildings have histories that are priceless to some people.

One option to help pay for the move would be to get a corporation to help sponsor the new city. But would you want to live in a New York City run by a mega-corporation?